Ferromagnetic device



Sept. 17, 1940. H, BR|NKMANN 2,214,898,

FERROMAGNETIC DEVICE Filed Sept. 22. 1938 Patented Sept. 17, I194()UNITED STATES f PATENT OFFICE'. i

14,398 FEBBOHAGNETIC DEVICE Hans Brlnkmann. Berlin,

CJarensAktiengesellschafL Germany.acompany A Dplieation SeptemberInGermanySe schim.

In the manufacture of compressed metal powder c ores for electromagnetsor for high frequency purposes and the like the metal powder .is mixedwith an insulating material and this 5 mixture is compressed to assumethe desired shape. The ferromagnetic bodies so obtained must be nttedwith supporting means made oi.' insulating material, for instance,namely, supporting means that shall enable the cores to be l0 mounted inthe respective devices and in a manner to be variable in position, as isrequired in Fmost cases. j

It is well known to interconnect such .cores -and supporting means byscrew threads provided l5 in the two. Theferromagneticmaterial howeverisfoundtobesbbrittlethatthecrestsofthe threads are liable to breaking,whereby insddition tothe decrease in mechanical strength the magneticproperties ofthe cores are varied. 9 it is customary tox' the'cores tosupports formed'ss a screw, for instance. In this case however' the boreprovided in the core and in which such supportingmeans is seated easilybreaks away. Also, connections made withtheaidofadhesivemeanshaveprovedtobeof littledurability. Q

The invention proposes to press a suitable insulating material aroundthe ferromagnetic material, namelyan insulating material the soften-l 0mpoincwmcnuwwertnmmstormbmni118 agent of the ferromagnetic material,that is, the agent irgwhich the metalparticles are em-'Iheinventionwillbeunderstoodfromthefob' lowing description,'referencebeinghed-to the Vdrswingirrwhichl'lg.iisasectionalviewrepresentingavariaAometerooress'providedbytheinventiomdl-isanendviewofanotherformofsuchavarldiameter core, 3 showi a sectiontaken .atv

l'illhtanglestol."ls'.2.`

-, 'l'hevariometercorcillustrated lprisesafcccgmpressedbodyI whosemetsiparticlesAareheldtogethex-byabinding-sgenttha'tma'ybea hardenedalkalinecondemed phenol-formaldehyde product, forexample.PressedsroundbodyiisabodytmadeofanartincislmateriaLwhichwmaybeacondensation product of the class towhichthe'bindf zz, iosa, seris Germany, assigner to Berlin-Tempelhof,

maybe secured in body 2 by the same moulding operation by which body 2'is pressedaround body I.

lThe body 2 when allowed to cool down after the pressing operation willshrink on body i and 5 thereby ilrmly enclosethis.

The material of which body 2 is made is' a bod conductor of heat.Therefore, in order to improve the arrangement shown .in 111g. 1clearances may be provided between thebodies l. 2 10 in the manner, forinstance, illustrated in Figs. 2', `3. The device here represented hasthe core i formed as'a hollow cylinder. Body 2 is so pressed around bodyi that there are clearances t between the two bodies, these beinginterconnected by u spoke members I which may be formed integral witheither bodyy i or body 2 or may be integral in part with body i and4 inpart with bodyl. In the caseshown by way oi' example body 2. is a hollowcylinder and like the. body 2 represented o in Fig. 1 is iitted withtrunnions 3. Body 2 is provided with a groove t or several such groovesintended to receive the variometer coil.`

, -An arrangement of the kind shown in Figs. u 11B/will eifectually leadaway the heat which `arises in body'i in consequence oi' the lossesoccuring in the high frequency field.

What is is:

1. A ferromagnetic device comprising anrst `moulded .body composed ofnnely divided fe-omagnetic material and a binding agent, a second bodyof insulating material having a thermal softening pointv lower than thatof said binding agent moulded around said rst lbody and outof contacttherewith, and supporting yrriembers--be- 85 Vtween said r'stanbceirgecond bodies and moulded thereto, said mem contacting said nrstbody vover only a small portion of the surface thereof. 2. A deviceas'deiined in claim 1,-having spoke members interconnecting the two saidbodies and 4 i formed yintegral with the ferromagnetic body. in Fig. 1com-'l l 3. A device according to claim 1, having spoke membersinterconnecting the two said bodiesl and formed integral'with saidinsulating body.

4. A devlce'as'deilne'd in claim l, having spokes 5 interconnecting thetwo said bodies and formed integralinpartwith oneoi'thesebodiesandin pmwith the other body.

v5.b A deviceaccording to claim l, wherein the'mssmbodienrejsubmnuanycyununeaime 5 `insulating bodyP having groovesfor positioning

